Time to consider solar energy for your farm?

Costs are down, equipment is dependable and long-term payback looks good, says ag engineer Kelly Lund

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A group of about 60 Alberta producers has installed solar-electric generating units over the past year and so far the decision is looking like a good one.

The installations were completed with support from the federal-provincial Growing Forward program. Quarterly performance feedback will provide the industry with important knowledge about how well these systems perform.

So far it looks good, says Kelly Lund, agricultural engineer with Alberta Agriculture and Rural Development, one of the people involved with the program and reviewing the data.

She says costs have dropped, the technology is reliable and long-term payback looks positive. Based on the Growing Forward farmer experience, here’s what she thinks they need to know.

Know the technology

Solar photovoltaic (PV) technology turns sun’s rays into electricity. That’s different than the technology used to generate heat.

  • Modules. The smallest functional solar PV unit that you can buy is called a solar ‘module’ (some refer to a single module as a ‘panel,’ but ‘module’ is more accurate). Modules are usually made up of from 36 to 80 solar cells, typically have rated power from 135 watts to 300+ watts, and may range in size from 26×60 inches to 53×66 inches, or other unique sizes. A number of modules wired in series and/or parallel makes up a solar array.
  • Inverters. Any grid-connected system will require inverters which take the direct current (DC) produced by the modules and convert it to alternating current (AC) and match it to the grid current.
  • Installation. Modules can be ground or roof mounted. Ground-mounted technology should use an adequate foundation such as concrete or driven-steel piles. Roof-mounted installations should be able to support the weight of the system. Engineered racking should be used to mount the modules as self-built racking will void the manufacturer’s warranty.

Where possible, modules should be mounted at a tilt angle that maximizes energy production based on the time of year. For optimum summer production, the tilt angle should be equal to the latitude of the location minus 20 degrees. For optimum winter production, the tilt angle should be equal to latitude plus 20. While ground-mounted systems can usually be adjusted, roof-mounted units on top of buildings are usually fixed. Lund says many producers opt for the lower cost of roof installations and accept the minor production loss that comes with lack of adjustment.

The size of installation is determined by legislation (Micro Generation Regulation) for those intending to be non-commercial producers. Producers are allowed to install units sized to cover the amount of electricity typically used on the operation on a yearly basis. If they do that, they are allowed to export excess electricity back to the grid for credit.

Producers should investigate the requirements for permits. In all cases, an electrical permit and electrical inspection will be required.

Reliable, low maintenance

Lund says solar PV technology has been around for a long time, is well tested, reliable, and requires little maintenance. Most carry some sort of electrical certification like Canadian Standards Association (CSA), Underwriters’ Laboratory (UL), or equivalent approval, and typically have 20- to 25-year pro-rated warranties. It is illegal in Canada to install any electrical equipment that does not have electrical certification.

Technology has not changed much, Lund says. One new style has reflectors on the opposite side to the solar panel, which is designed to improve efficiency. A number of installations in this program used this reflector technology, and results are pending as to whether the actual annual production will match the manufacturer’s claims. There are some differences in manufacturer claims in terms of efficiency, whether a module is 14 per cent efficient or 17 per cent, for example, but there is not a wide spread between manufacturers, she says. The most critical issue is likely how solvent the manufacturer is, and whether it will stay in business long enough to support a warranty.

Installed costs have dropped

The biggest news is likely the dramatic drop in cost of installations, due to equipment prices coming down. “The first handful of Growing Forward projects came in at $5.50 to $6/watt installed. By the end of the program that had dropped to $4.15 to $3.60,” says Lund. “Now we’re even hearing quotes of under $3.60.”

That means for a 10-kW system, what was a $55,000 system is now under $40,000, she says. Some people are doing their own installations which lower costs even more.

“So if people follow basic good business protocol and get competitive quotes they should be able to get installations done for under $4 a watt by an experienced third-party installer,” Lund says.

On the cost recovery side, the news is good. Local wire service providers are getting more familiar with applications from individuals who want to become micro-generators and that application process is getting faster. And new retailers that have moved into Alberta are offering micro-generators a price premium of $0.15 /kWh, although this price premium should be considered temporary, subject to the government review of the Micro Generation Regulation occurring at the end of 2013.

Long-term payback looks positive

With today’s cost, Lund says that depending on the owner’s financing or borrowing costs, many installations today show solar-generated electricity to be at grid parity, where the price per kWh of solar electricity is equal to or less than the cost of electricity from the grid, on a long-term (i.e. 25-year) basis.

“You can see producers asking themselves if they are going to be able to buy power from the grid for that price 10 or 20 years down the road and coming to the conclusion they likely won’t,” says Lund.

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